A15232. Permutation

Recall that a permutation of length $n$ is an array where each element from $1$ to $n$ occurs exactly once.

For a fixed positive integer $d$ , let's define the cost of the permutation $p$ of length $n$ as the number of indices $i$ $(1 \le i < n)$ such that $p_i \cdot d = p_{i + 1}$ .

For example, if $d = 3$ and $p = [5, 2, 6, 7, 1, 3, 4]$ , then the cost of such a permutation is $2$ , because $p_2 \cdot 3 = p_3$ and $p_5 \cdot 3 = p_6$ .

Your task is the following one: for a given value $n$ , find the permutation of length $n$ and the value $d$ with maximum possible cost (over all ways to choose the permutation and $d$ ). If there are multiple answers, then print any of them.

The first line contains a single integer $t$ ( $1 \le t \le 500$ ) — the number of test cases.

The single line of each test case contains a single integer $n$ ( $2 \le n \le 2 \cdot 10^5$ ).

The sum of $n$ over all test cases does not exceed $2 \cdot 10^5$ .

For each test case, print the value $d$ in the first line, and $n$ integers in the second line — the permutation itself. If there are multiple answers, then print any of them.